printf会改变原始数据。改用串口原生函数。timeout改大点。否则不能发完。

Core/Src/main.c

@@ -65,18 +65,18 @@ static void MX_USART3_UART_Init(void);
 #include <stdio.h>
 
 // 重定向fputc函数到USART1
-int _write(int file, char *ptr, int len)
-{
-  HAL_UART_Transmit(&huart1, (uint8_t*)ptr, len, HAL_MAX_DELAY);
-  return len;
-}
-
-int fputc(int ch, FILE *f)
-{
-  uint8_t c = ch;
-  HAL_UART_Transmit(&huart1, &c, 1, HAL_MAX_DELAY);
-  return ch;
-}
+// int _write(int file, char *ptr, int len)
+// {
+//   HAL_UART_Transmit(&huart1, (uint8_t*)ptr, len, HAL_MAX_DELAY);
+//   return len;
+// }
+//
+// int fputc(int ch, FILE *f)
+// {
+//   uint8_t c = ch;
+//   HAL_UART_Transmit(&huart1, &c, 1, HAL_MAX_DELAY);
+//   return ch;
+// }
 
 int __io_putchar(int ch)
 {
@@ -121,11 +121,12 @@ int main(void)
   MX_USART3_UART_Init();
   /* USER CODE BEGIN 2 */
   // 启动 USART2 DMA 接收
-  HAL_UART_Receive_DMA(&huart2, rx_buf, sizeof(rx_buf));
-  // 使能 USART2 空闲中断
-  __HAL_UART_ENABLE_IT(&huart2, UART_IT_IDLE);
+  // HAL_UART_Receive_DMA(&huart2, rx_buf, sizeof(rx_buf));
+  // // 使能 USART2 空闲中断
+  // __HAL_UART_ENABLE_IT(&huart2, UART_IT_IDLE);
 
   printf("USART2 DMA + IDLE 中断接收已启动\r\n");
+  uint8_t i = 0;
   /* USER CODE END 2 */
 
   /* Infinite loop */
@@ -134,15 +135,18 @@ int main(void)
   {
     /* USER CODE END WHILE */
     // 用 printf 输出（printf 已经重定向到 USART2）
-    printf("hello world task 2\r\n");
+    // printf("hello world task 2\r\n");
 
     // 发送一个字符串到UART2
     const char *msg = "12345hhl789099999999999999999999999999999999999999999999999999999999899999999999999999999999999999999999999999999fdasfdeqrftewqtrewfgdaf9999999999999fdasffdsafdsafdsafdsafddsafsdddddddddddddddddd88888888888888888888888888888888888888888ddddddddddddddddddssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss99999999999999999999999999999999999999999990078rewqreqwrewqrewqfdsafdsafewqfdsafewqfdsafew  fdsafe77xxy888";
-    HAL_UART_Transmit(&huart2, (uint8_t*)msg, strlen(msg), HAL_MAX_DELAY);
-
-    printf("Received data: %s\r\n", rx_buf);
-    memset(rx_buf, '\0', 500);
-    printf("111\r\n");
+    // HAL_UART_Transmit(&huart2, (uint8_t*)msg, strlen(msg), HAL_MAX_DELAY);
+    //
+    // printf("Received data: %s\r\n", rx_buf);
+    // memset(rx_buf, '\0', 500);
+    // printf("%02X\r\n",i++);
+    // printf("%d\r\n",strlen(msg));
+    HAL_UART_Transmit(&huart1, msg, strlen(msg), 100);
+    i++;
     HAL_Delay(1000);
     /* USER CODE BEGIN 3 */
   }

Core/Src/stm32f1xx_it.c

@@ -246,7 +246,7 @@ void USART2_IRQHandler(void)
     HAL_UART_DMAStop(&huart2);
 
     uint32_t received_len = sizeof(rx_buf) - __HAL_DMA_GET_COUNTER(huart2.hdmarx);
-    printf("Received %lu bytes: %.*s\r\n", received_len, (int)received_len, rx_buf);
+    // printf("Received %lu bytes: %.*s\r\n", received_len, (int)received_len, rx_buf);
 
     HAL_UART_Receive_DMA(&huart2, rx_buf, sizeof(rx_buf)); // 重新启动
   }